Posted
by
Soulskillon Friday January 11, 2013 @05:20PM
from the stately-grace dept.

SchrodingerZ writes "A new video was released yesterday by NASA from the GRAIL mission probes, which ended their mission last month as they impacted the lunar surface. 'Dramatic' footage was captured by the probe Ebb on December 14th. The video was taken from the 'MoonKAM (Moon Knowledge Acquired by Middle school Students) cameras. It shows the view of Ebb flying at an altitude of 6 miles (10 km) above the Moon's northern hemisphere in the vicinity of Jackson crater (22.4N 163.1W).' Two videos were released, one from the fore and one from the aft of the probe, showing a forwards and backwards time lapse containing 931 and 1,489 pictures each of the lunar terrain. The footage was part of the probes' final systems check before they shut down and were sent into a controlled impact to a predetermined location."

Hey armchair astrophysicists... A thought occurred to me when watching this video. Since the moon has a negligible atmosphere, how close can a spacecraft reliably orbit it? Other than the ability to make sure eccentricity is near 0, what would stop a satellite from orbiting a few hundred meters above the tallest peak?

I've even heard it more-broadly stated that there are NO long-term stable lunar orbits. It's an issue for orbital debris: since (1) objects don't burn up on entry, and (2) an uncontrolled orbit is impossible to predict in the long term, therefor all lunar orbiters should be removed rather than abandoned and lunar deorbits should be targeted rather than random.